Medicament inhalation delivery devices and methods for using the same

ABSTRACT

A medicament delivery device for administering a medicament to a user includes a medicament reservoir and an entrance port and an exit port each disposed adjacent the reservoir. A gas chamber disposed adjacent the entrance port. The device includes a pressurizing mechanism operable to pressurize said gas chamber to at least a prescribed pressure. A first frangible membrane extends across the entrance port and separates the reservoir from the gas chamber. A second frangible membrane extends across the exit port. When the pressurizing mechanism is attached, at least one of the first and second membranes is responsive to the prescribed pressure in the gas chamber to burst to allow gas to flow through the entrance port and the reservoir and to carry the medicament through the exit port.

RELATED APPLICATIONS

This application is a continuation application of Ser. No. 10/792,583,filed Mar. 3, 2004, now U.S. Pat. No. ______ which is a continuationapplication of Ser. No. 09/758,776, filed Jan. 12, 2001, now U.S. Pat.No. 6,722,364 each of which are herein incorporated by reference intheir entirety.

FIELD OF THE INVENTION

The present invention relates to medicament delivery devices and, moreparticularly, to devices for administering inhalable medicaments.

BACKGROUND OF THE INVENTION

Inhalers are commonly used to deliver various medicaments to users viathe user's nose or mouth. Such medicaments increasingly include drypowders. A number of considerations affecting the efficacy of deliverymay be presented, particularly in the case of dry powders. For example,it may be important to ensure that the appropriate dose is metered andexpressed, that the medicament is properly dispersed in the conveyingfluid (e.g., the carrier gas), that the delivery device is not undulysusceptible to user error in operation, and/or that undue inhalationstrength is not required. Further considerations may include theoperating complexity, portability and size of the delivery device.Because inhalation therapy often requires numerous applications, thecost of providing the dosage may be of particular importance.

SUMMARY OF THE INVENTION

According to embodiments of the present invention, a medicament deliverydevice for administering a medicament to a user includes a medicamentreservoir and an entrance port and an exit port each disposed adjacentthe reservoir. A gas chamber is disposed adjacent the entrance port. Thedevice includes a pressurizing mechanism operable to pressurize the gaschamber to at least a prescribed pressure. A first frangible membraneextends across the entrance port and separates the reservoir from thegas chamber. A second frangible membrane extends across the exit port.When the pressurizing mechanism is attached, at least one of the firstand second membranes is responsive to the prescribed pressure in the gaschamber to burst to allow gas to flow through the entrance port and thereservoir and to carry the medicament through the exit port.

The pressurizing mechanism may include a compressible blister definingthe gas chamber and operable to pressurize the gas chamber to at leastthe prescribed pressure. The device may include: a first sheet includingthe compressible blister formed therein; a second sheet defining thereservoir therein; and an intermediate layer disposed between the firstand second sheets, the first and second membranes forming a part of theintermediate layer.

According to further embodiments of the present invention, a medicamentdelivery device for administering a medicament to a user includes amedicament reservoir and an entrance port and an exit port each disposedadjacent the reservoir. The device includes a compressible blisterdefining a gas chamber and operable to pressurize the gas chamber to atleast a prescribed pressure. A frangible membrane extends across theentrance port and separates the reservoir from the gas chamber. When theblister is compressed, the membrane is responsive to the prescribedpressure in the gas chamber to burst to allow gas to flow through theentrance port and the reservoir and to carry the medicament through theexit port.

According to further embodiments of the present invention, a method foradministering a medicament to a user includes providing a medicamentdelivery device including: a medicament reservoir; an entrance port andan exit port each disposed adjacent the reservoir; a gas chamberdisposed adjacent the entrance port; a pressurizing mechanism operableto pressurize the gas chamber to at least a prescribed pressure; a firstfrangible membrane extending across the entrance port and separating thereservoir from the gas chamber; and a second frangible membraneextending across the exit port. The pressurizing mechanism is actuatedto generate the prescribed pressure in the gas chamber, whereupon atleast one of the first and second membranes bursts to allow gas to flowthrough the entrance port and the reservoir and to carry the medicamentthrough the exit port.

According to further embodiments of the present invention, a method foradministering a medicament to a user includes providing a medicamentdelivery device including: a medicament reservoir; an entrance port andan exit port each disposed adjacent the reservoir; a compressibleblister defining a gas chamber and operable to pressurize the gaschamber to at least a prescribed pressure; and a frangible membraneextending across the entrance port and separating the reservoir from thegas chamber. The blister is compressed to generate the prescribedpressure in the gas chamber, whereupon the frangible membrane bursts toallow gas to flow through the entrance port and the reservoir and tocarry the medicament through the exit port.

Objects of the present invention will be appreciated by those ofordinary skill in the art from a reading of the figures and the detaileddescription of the preferred embodiments which follow, such descriptionbeing merely illustrative of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention and,together with the description, serve to explain principles of theinvention.

FIG. 1 is a perspective view of a delivery device according toembodiments of the present invention;

FIG. 2 is an exploded, perspective view of a dispenser forming a part ofthe delivery device of FIG. 1;

FIG. 3 is a center cross-sectional view of the dispenser of FIG. 2;

FIG. 4 is a center cross-sectional view of the dispenser of FIG. 2wherein the dispenser is in a partially actuated position;

FIG. 5 is a perspective view of an intermediate sheet of a dispenseraccording to a further embodiment of the present invention;

FIG. 6 is an exploded, perspective view of a dispenser according to afurther embodiment of the present invention;

FIG. 7 is a center cross-sectional view of a dispenser according to afurther embodiment of the present invention;

FIG. 8 is a center cross-sectional view of the dispenser of FIG. 7wherein a cap thereof is removed;

FIG. 9 is a center cross-sectional view of a dispenser according to afurther embodiment of the present invention;

FIG. 10 is a center cross-sectional view of a dispenser according to afurther embodiment of the present invention, wherein the dispenser isshown in a partially actuated position;

FIG. 11 is a center cross-sectional view of a dispenser according to afurther embodiment of the present invention, wherein the dispenser isshown in a partially actuated position;

FIG. 12 is a side elevational view of a dispenser according to a furtherembodiment of the present invention;

FIG. 13 is an exploded, perspective view of the dispenser of FIG. 12prior to assembly;

FIG. 14 is a perspective view of a delivery device according to afurther embodiment of the present invention, wherein a delivery tubethereof is in a folded position;

FIG. 15 is a perspective view of the delivery device of FIG. 15, whereinthe delivery tube thereof is shown in an extended, operative position;

FIG. 16 is a perspective view of a delivery device according to afurther embodiment of the present invention, wherein a delivery tubethereof is shown in an extended position;

FIG. 17 is a perspective view of the delivery device of FIG. 16, whereinthe delivery tube thereof is shown in a retracted position;

FIG. 18 is a perspective, fragmentary view of a delivery deviceaccording to a further embodiment of the present invention;

FIG. 19 is a perspective, schematic view of a delivery device accordingto a further embodiment of the present invention; and

FIG. 20 is a perspective, fragmentary view of a delivery deviceaccording to a further embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout. In the figures, certaincomponents and the thicknesses of some layers may be exaggerated forclarity.

With reference to FIGS. 1-4, a medicament inhalation delivery device 101according to embodiments of the present invention is shown therein. Thedelivery device 101 includes a dispenser 100 and a delivery tube 180(see FIG. 1). The dispenser 100 includes a pressurizing mechanism 110, astorage volume 116 and a diffuser tube 120. The dispenser 100 contains aquantity of a desired medicament 5 (see FIG. 3) in the storage volume116. Preferably, the quantity of medicament corresponds to a singletherapeutic dose. The medicament 5 may be a sterile, dry powdermedicament.

Generally, and as discussed in greater detail below, the medicament 5may be delivered to the airway of the user, typically to the mouth ornose of the user by locating the free end of the delivery tube 180adjacent the user's mouth or nose and actuating the pressurizingmechanism 110. In this manner, a carrier gas 111 is forced through thestorage volume 116, the diffuser tube 120 and the delivery tube 180. Asthe carrier gas 111 flows through the storage volume 116, the medicament5 becomes entrained in the gas 111 and is transported and expelled fromthe delivery tube with the gas to the user. Optionally, the deliverytube 180 may be omitted, in which case the open end of the diffuser tube120 may be directly located adjacent the mouth or nose of the user.

As best seen in FIGS. 2 and 3, the dispenser 100 includes an upper sheet140, a lower sheet 160 and an intermediate sheet 150. The relativethickness of the intermediate sheet 150 is exaggerated in FIGS. 3 and 4for clarity. The upper sheet has a blister 142 and a cone-shaped channel144 formed therein. The blister 142 and the channel 144 are surroundedby marginal portions 146A, 146B and 146C (FIG. 3). The lower sheet 160has a reservoir 166 formed therein and marginal portions 162, 164surrounding the reservoir 166.

The sheets 140, 150, 160 are relatively configured and disposed suchthat the upper sheet 140 is joined to the intermediate sheet 150, andthereby to the lower sheet 160, by the marginal portions 146A and 146C(see FIG. 2). While the intermediate sheet 150 is shown as extending thefull length of the dispenser 100, the intermediate sheet 150 may beabbreviated and may comprise multiple, discrete sheets. For example, onesuch sheet may include the membrane 152 as described below and another,separate such sheet may include the membrane 154 as described below.

A central portion 146B of the upper sheet 140 is laminated to theintermediate sheet 150 and overlies the reservoir 166. The length D ofthe reservoir 166 is greater than the length C of the central portion146B so that an entrance opening or port 114 and an exit opening or port118 are defined on either side of the central portion 146B. The ports114 and 118 have lengths A and B, respectively. The intermediate sheet150 includes a first or entrance membrane 152 (indicated by dashed linesin FIG. 2) which extends fully across the port 114. The intermediatesheet 150 also includes an exit membrane 154 (indicated by dashed linesin FIG. 2) which extends fully across the port 118. In this manner, thereservoir 166, the entrance membrane 152, the exit membrane 154 and thecentral portion 146B define the reservoir 166 within which themedicament 5 is fully encapsulated in the storage volume 116.

The blister 142 and the marginal portion 162 form the pressurizingmechanism 110 and define a gas chamber 112. The gas chamber 112 isdisposed immediately adjacent the port 114 and is fully sealed from thestorage volume 116 by the entrance membrane 152. Similarly, the channel144 and the marginal portion 164 form the diffuser tube 120 and define apassage 122 and a delivery opening 124. The passage 122 is disposedimmediately adjacent the port 118 and is fully sealed from the storagevolume 116 by the exit membrane 154.

The upper and lower sheets 140, 160 are preferably thermoformed from asuitable polymeric or elastomeric material. More preferably, the upperand lower sheets 140, 160 are formed of a co-laminated or co-extrudedfilm including a layer of thermoformable polyethylene terephthalate(PET) on the exterior thereof and a layer of heat-sealable polyethyleneon the interior thereof. The intermediate layer 150 is preferably formedof a layer of polyethylene. Preferably, the intermediate layer 150 has athickness of between about ½ and 4 mil. Preferably, the intermediatelayer 150 has a burst pressure of between about 4.4 and 89.0 Newtons.Preferably, the intermediate layer 150 has a tensile strength of betweenabout 10 and 50 MPascals.

The gas chamber 112 preferably has a volume of between about 0.2 and 10milliliters. The gas in the gas chamber 112 and the gas in the storagevolume 116 can be the same or different gases. These gases may be air orother suitable gases. For example, noble gases, N₂, Ar or He may beused.

The medicament 5 may be any substance which produces a clinically usefulresult. By “clinically useful result” is meant clinically adequateprevention or treatment of a disease or condition by administration of asubstance. Examples include, but are not limited to, clinically adequatecontrol of blood sugar levels (insulin), clinically adequate managementof hormone deficiency (PTH, Growth Hormone, etc.), expression ofprotective immunity (vaccines), prevention of thrombosis (heparin orderivatives), alleviation or prevention of pain (antimigraines, opiods,etc.), infection control (antibiotics), allergy control, or clinicallyadequate treatment of toxicity (antitoxins). More preferably, themedicament 5 is a dry powder consisting of a substance producing aclinically useful result. Such substances may be incorporated ascomponents of mixtures with other excipients by processes which areknown in the art. Such processes may include, but are not limited to,freeze drying of mixtures followed by dry blending, spray drying andsupercritical processing methods.

The dispenser 100 (or a series of dispensers 100) may be formed on a webin a manner similar to that commonly employed to form blister packs. Theblister 142 and the channel 144 are thermoformed in a web correspondingto the upper sheet 140, and the reservoir 166 is thermoformed in a webcorresponding to the lower sheet 160. A web corresponding to theintermediate sheet 150 is inserted between the webs corresponding to thesheets 140 and 160. The webs corresponding to the sheets 140, 150 and160 are then heat sealed in the layered configuration as shown in FIG. 3with the medicament 5 disposed in the reservoir 160. Preferably, themedicament 5 is first placed in the reservoir 166, the web correspondingto the sheet 150 is thereafter heat sealed to the web corresponding tothe sheet 160 to package the medicament 5, and the web corresponding tothe sheet 140 is thereafter heat sealed to the opposite side of the webcorresponding to the sheet 150 to form a unitary dispenser 100. Thedispenser 100 is then die cut or otherwise severed from the remainder ofthe webs.

For inhalation through the nose, the dispenser 100 is preferably usedwithout the delivery tube 180. For inhalation through the mouth, thedispenser 100 may be mounted in the opening 182B of the delivery tube180 by means of slots 184 (FIG. 1). The delivery opening 182A of thedelivery tube 180 is placed adjacent the user's mouth or, alternatively,the delivery opening 124 of the diffuser tube 120 is placed adjacent theuser's nose. Preferably, in operation, the dispenser 100 is orientedsuch that the blister 142 is on top and the reservoir 166 is on bottom.

The user then begins inhaling through the delivery tube 180 or thediffuser tube 120. As the user is inhaling, the user applies acompressive load to the blister 142 as indicated by the direction arrowsL in FIG. 4. This may be conveniently and effectively accomplished bysqueezing or depressing the blister 142 and the marginal portion 162between the user's thumb and one or more fingers. As the user compressesthe blister 142, the pressure within the gas chamber 112 is increased,thereby applying an increasing load to the entrance membrane 152. When aprescribed pressure is created in the gas chamber 112, the entrancemembrane 152 will burst, placing the gas chamber 112 in fluidcommunication with the storage volume 116. The exit membrane 154 issubstantially immediately thereafter loaded by the same pressure andbursts as well, placing the storage volume 116 in fluid communicationwith the passage 122. As a result, a continuous flow path is providedfrom the gas chamber 112 to the delivery opening 124. The gas 111originally in the gas chamber 112 is displaced at high velocity throughthe ports 114, 118 and the storage volume 116 such that the gas 111aerosolizes the medicament 5 and a plume 5A including the medicament 5is forced out of or expelled from the dispenser 100 as shown in FIG. 4.The diffuser tube 120 and/or the delivery tube 180 enable expansion andmixing of the plume and also allow the plume 5A to slow before ultimatedelivery to the user.

It will be appreciated that the carrier gas 111 which aerosolizes themedicament may include some or all of the gas stored in the storagevolume 116. Moreover, dispensers according to the present invention maybe configured such that the gas originally stored in the gas chamber 112does not ultimately form a part of the plume 5A, but rather this gasdisplaces a downstream quantity of gas which aerosolizes the medicament5. Means other than the thermoformed reservoir 166 may be employed tohold the medicament 5 in the flow path of the gas. For example, thereservoir may be separately formed from the pressurizing mechanism 110or the diffuser tube 120, for example.

The delivery device 101 and the dispenser 100 provide a number ofadvantages. The dispenser 100 is cost effective to manufacture and maycorrespond to the cost of simply packaging single doses of themedicament 5 itself. The delivery device 101 and the dispenser 100 areeasy to use. The dispenser 100 can provide a single, accurately measureddose. Because of the provision of the pressurizing mechanism 110, thedispenser 100 does not require a high degree of inspiratory effort onthe part of the user to deliver the full, prescribed dose. The dispenser100 may be disposable, so that no cleaning or reloading is required.

The preferred properties of the membranes 152, 154 and theconfigurations and dimensions of the blister 142 and the reservoir 166will depend on the amount and characteristics of the medicament 5, aswell as the operational characteristics desired. The prescribed pressureshould be high enough to create a sufficient carrier gas velocity todispense and deaggregate the medicament 5 to thereby create a cloud ofthe medicament 5 which is suitable for inhalation and which can propelsubstantially all of the medicament 5. A residue of the medicament 5 mayremain in the reservoir 166 after application. Preferably, the amount ofresidue is no more than 10% of the original amount of medicament 5.However, the prescribed pressure is preferably sufficiently low as tonot require undue effort from the user to generate the prescribedpressure in the gas chamber 112.

The prescribed pressure of the dispenser 100 necessary to deliver themedicament 5 will depend on the effective burst pressure and tensilestrength of one or both of the membranes 152 and 154. The performance ofthe dispenser 100 may be varied by appropriately selecting andconfiguring the materials of the membranes to provide the effectiveburst pressures and tensile strengths of the membranes 152 and 154.

For some applications, it may be desirable to provide both of themembranes 152 and 154 with substantially the same effective burstpressures and/or tensile strengths. This may be accomplished by formingthe membranes 152 and 154 of the same material and with the samedimensions.

For some applications, it may be desirable to provide one of themembranes 152, 154 with a higher effective burst pressure and/or tensilestrength than the other membrane 152, 154. It has been found that a morecomplete emitted dose (i.e., less residual medicament remaining in thereservoir 166 following activation) may be achieved when one of themembranes 152, 154 ruptures at a pressure significantly below theprescribed pressure. In particular, it has been found that for someembodiments the residual dose is substantially reduced or effectivelyeliminated when the entrance membrane 152 is adapted to burst at apressure less than the pressure required to burst the exit membrane 154.Preferably, the entrance membrane 152 is adapted to burst at betweenabout 20 and 80% of the pressure at which the exit membrane 154 bursts.

The membranes 152, 154 may be adapted to burst at different pressures byappropriate selection of the relative materials, thicknesses and/ordifferent sizes of ports 114, 118. Alternatively or additionally, thefollowing features may be used to provide differential burstingpressures. These features may be used individually or in combination.

With reference to FIG. 5, an intermediate sheet 250 as shown therein maybe substituted for the intermediate sheet 150 of the dispenser 100. Theintermediate sheet 250 includes an entrance membrane 252 and an exitmembrane 254 (each indicated by dashed lines) corresponding to themembranes 152 and 154, respectively. The intermediate sheet 250 may beformed in the same manner as the intermediate sheet 150 except that thesheet 250 is further provided with embossments 252A and 254A on themembranes 252 and 254 to control the break pattern of the film. Theembossments can be depressions, deformations, scored regions or reducedthickness regions in the film of the sheet 250 and serve to providepreferential release portions or weakened locations.

The embossments 252A and 254A may have different patterns (as shown) orthe same pattern. One of the embossments 252A, 254A may be omitted. Inparticular, the embossment 254A may be omitted in order to provide themembrane 252 with a lower effective burst pressure than the membrane254. An alternative embossment pattern includes multiple small pointswhich, upon application of a relatively low pressure, will break toconvert the selected membrane(s) into a mesh. The embossments 252A, 254Amay be formed by any suitable means, for example, by mechanical and/orheat stamping.

With reference to FIG. 6, a dispenser 300 according to a furtherembodiment is shown therein. The dispenser 300 includes upper and lowersheets 340 and 360 corresponding to the upper and lower sheets 140 and160, respectively, and can be constructed in the same manner as thedispenser 100 except that the intermediate sheet 150 is replaced withintermediate sheets 350A and 350B. The sheet 350A includes the entrancemembrane 352 (indicated by dashed lines) and the sheet 350B includes theexit membrane 354 (indicated by dashed lines). The sheets 350A, 350B areformed of oriented films. As used herein, “oriented film” means a filmwhich is drawn in the direction of flow during or after extrusion.Preferably, the sheets 350A, 350B are formed of uniaxially orientedfilms.

Preferably, the films of the sheets 350A, 350B are oriented at differentangles and, more preferably, at an angle of about 90 degrees withrespect to one another. Most preferably, the film of the sheet 350A(and, thus, the film of the entrance membrane 352) is oriented to tearalong an axis P substantially parallel to the flow path and the film ofthe sheet 350B (and, thus, the film of the exit membrane 354) isoriented to tear along an axis R substantially perpendicular to the flowpath.

With reference to FIGS. 7 and 8, a dispenser 400 according to a furtherembodiment of the present invention is shown therein. The dispenser 400corresponds to the dispenser 100 except that the dispenser 400 isfurther provided with an end cap assembly 490. The end cap assembly 490includes a cap 492 that is removably mounted on the diffuser tube 420 asshown in FIG. 7. A connector string 494 is secured to the cap 492,extends through the passage 422, and is secured to the exit membrane454.

In use, the user first pulls the cap 492 away from the diffuser tube420, thereby tearing and/or pulling a portion or all of the exitmembrane 454 away as shown in FIG. 8. In this manner, the port 418 ispartially or fully opened at a desired dispensing time. The user maythen actuate the dispenser 400 in the manner described above with regardto the dispenser 100.

With reference to FIG. 9, a dispenser 500 according to furtherembodiments of the present invention is shown therein. The dispenser 500corresponds to the dispenser 100 except as follows. A piercing member553 can be molded into or otherwise secured to the lower sheet 560(e.g., prior to heat sealing the upper, lower and intermediate sheets).The piercing member 553 extends into the storage volume 116 below theentrance membrane 552.

When the blister 542 is depressed, the pressure therein causes theentrance membrane 552 to deform or bulge downwardly into contact withthe piercing member 553. In this manner, the membrane 552 may bepre-pierced or burst at a pressure lower than the pressure required toburst the exit membrane 554.

With reference to FIG. 10, a dispenser 600 according to furtherembodiments of the present invention is shown therein in a partiallyactuated position. The dispenser 600 corresponds to the dispenser 100except as follows. A piercing member 653 is molded into or otherwisesecured to the upper sheet 640 and, more particularly, into the blister642. Prior to actuation of the pressurizing mechanism 610, the piercingmember 653 extends downwardly into the gas chamber 612 and is positionedsuspended above the entrance membrane 652.

When the blister 642 is depressed, the piercing member 653 is displacedand moves to contact the entrance membrane 652. In this manner, themembrane 652 may be pre-pierced or burst at a pressure lower than thepressure required to burst the exit membrane 654.

With reference to FIG. 11, a dispenser 700 according to furtherembodiments is shown therein in a partially actuated position. Thedispenser 700 corresponds to the dispenser 100 except as follows. Thestiffness, elasticity and other appropriate characteristics of the uppersheet 740, the lower sheet 760 and the intermediate sheet 750 areselected such that, as the blister 742 is depressed in a direction M,the portions of the several sheets 740, 750, 760 upstream of theentrance port 714 (collectively, the dispenser portion 703) stretchlaterally in the direction N relative to the portions of the sheets 740,750, 760 downstream of the entrance port 714 (collectively, thedispenser portion 705). This stretching increases the length E of theport along the direction N (i.e., substantially along the length of theflow path) and thereby distorts the entrance membrane 752. Suchdistortion creates non-uniformity in the entrance membrane 752 andresultant stress concentrations. In this manner, the entrance membrane752 may be burst at a pressure lower than the pressure required to burstthe exit membrane 754.

With reference to FIGS. 12 and 13, a dispenser 800 according to furtherembodiments of the present invention is shown therein. The dispenser 800has an upper sheet 840, an intermediate sheet 850 and a lower sheet 860corresponding to the sheets 140, 150 and 160, respectively, except asfollows.

The upper sheet 840 and the lower sheet 860 are integrally formed as aclam shell member 810 and are pivotably joined by hinge portions 812.Cone shaped diffuser channels 844A and 844B are formed in the sheets 840and 860, respectively. To assemble the dispenser 800, the sheets 840,860 are folded or pivoted about the hinges 812 with the sheet 850positioned therebetween. The channels 844A, 844B combine to form anenlarged conical diffuser tube 820. Optionally, the channel 844B may bereplaced with a planar portion as is the dispenser 100.

The dispenser 800 has a generally accordion or bellows shaped blister842. The blister 842 has generally vertically extending ring shapedwalls 842A and ring shaped, rounded connecting walls 842B. The walls842A are preferably substantially concentric with each other and withthe walls 842B. The blister 842 is tapered such that the diameters ofthe walls 842A, 842B decrease incrementally toward the upper end of theblister 842.

When the blister 842 is depressed, the walls 842 tend to guide theblister 842 in a vertical direction V which is preferably collinear withthe common central axis of the walls 842A, 842B. The rounded walls 842Ballow the blister 842 to collapse easily against the underlyingsegments. The telescoping shape of the blister 842 helps to preventroll-over of the blister as it is being depressed.

With reference to FIGS. 14 and 15, a delivery device 901 according tofurther embodiments of the present invention is shown therein. Thedelivery device 901 includes a delivery tube 980 and a dispenser 900corresponding to the dispenser 100. The delivery tube 980 is configuredand formed of a suitable material such that the delivery tube 980 isfoldable. Suitable materials may include polystyrene, polyvinyl chloride(PVC), polypropylene, polyethylene, polyester or ABS. The delivery tube980 may be maintained in a folded position, as shown in FIG. 14, suchthat portions 986A and 986B of the delivery tube 980 are joined along afold 981. This position may be particularly advantageous for storing thedelivery device 901. When the user wishes to administer a dose from thedispenser 900, the user may unfold the portion 986B about the fold 981to extend the delivery tube 980 in the delivery position as shown inFIG. 15.

With reference to FIGS. 16 and 17, a delivery device 1001 according tofurther embodiments of the present invention is shown therein. Thedelivery device 1001 includes a dispenser 1000 corresponding to thedispenser 100. The delivery device 1001 further includes a delivery tube1080. The delivery tube 1080 includes a plurality of telescopingsegments 1086A, 1086B, 1086C. For storage, the delivery tube 1080 may beslidably nested or compressed as shown in FIG. 17. The delivery tube1080 may thereafter be re-extended as shown in FIG. 16 for use.

With reference to FIG. 18, a delivery device 1101 according to furtherembodiments of the present invention is shown therein. The deliverydevice 1101 includes a dispenser 1100 corresponding to the dispenser100. The delivery device 1101 further includes a delivery tube 1180. Thedelivery tube 1180 corresponds to the delivery tube 180 except that aplurality of baffles 1188A and 1188B are secured to the interior surface1181 of the delivery tube 1180 and extend radially inwardly therefrom.The baffles 1188A, 1188B are preferably integrally molded into thedelivery tube 1180. The baffles 1188A and the baffles 1188B extend fromopposing sides of the delivery tube 1180 and are arranged in asequentially alternating fashion. The baffles 1188A, 1188B may serve toslow the plume of medicament from the dispenser 1100. The baffles 1188A,1188B may also serve to deaggregate the medicament and also to induceadditional turbulence in the carrier gas stream to aid in mixing of themedicament with the carrier gas stream.

With reference to FIG. 19, a delivery device 1201 according to furtherembodiments of the present invention is shown therein. The deliverydevice 1201 includes a dispenser 1200 corresponding to the dispenser100. The delivery device 1201 further includes a delivery tube 1280. Ahelical rib 1287 is secured to and extends radially inwardly from theinterior surface 1281 of the delivery tube 1280. The rib can beintegrally molded with the delivery tube 1280. The helical rib 1287extends down at least a portion of the length of the interior wall ofthe delivery tube 1280. Preferably, the rib 1287 has a radiallyextending height of between about ⅕ and ⅘ of the exit tube diameter. Thehelical rib 1287 may serve the functions discussed above with regard tothe baffles 1188A, 1188B.

With reference to FIG. 20, a delivery device 1301 according to furtherembodiments of the present invention is shown therein. The deliverydevice 1301 includes a dispenser 1300 corresponding to the dispenser100, for example. The delivery device 1301 further includes a deliverytube 1380 corresponding to the delivery tube 180 except as follows. Amesh or screen 1389 is positioned in and secured to the interior surface1381 of the delivery tube 1380. Preferably, the screen 1389 extendsfully across the width of the delivery tube 1380. The preferred meshsize of the screen 1389 will depend on the optimum particle size of thepowder to be delivered. The screen 1389 is preferably formed of aplastic material. The screen 1389 may serve the functions discussedabove with regard to the baffles 1188A, 1188B.

As a further alternative, baffles corresponding to the baffles 1188A,1188B may be secured to and extend radially inwardly from the interiorwall or the delivery opening 124 of the diffuser tube 120, for example.Similarly, a helical rib corresponding to the helical rib 1287 may beprovided in the diffuser tube 120, for example. Also, as a furtheralternative, a screen corresponding to the screen 1389 may be mounted inthe diffuser tube 120 or the port 124.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although a few exemplary embodiments ofthis invention have been described, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe claims. Therefore, it is to be understood that the foregoing isillustrative of the present invention and is not to be construed aslimited to the specific embodiments disclosed, and that modifications tothe disclosed embodiments, as well as other embodiments, are intended tobe included within the scope of the appended claims. The invention isdefined by the following claims, with equivalents of the claims to beincluded therein.

1. A medicament delivery device for administering an inhalablemedicament to a user, said device comprising: a medicament reservoir; anentrance port and an exit port each disposed adjacent said reservoir; agas chamber disposed adjacent said entrance port; a pressurizingmechanism operable to pressurize said gas chamber to at least aprescribed pressure; a first frangible membrane extending across saidentrance port and separating said reservoir from said gas chamber; asecond frangible membrane extending across said exit port; a tubedisposed adjacent said exit port and defining a delivery openingopposite said exit port; and, a piercing member configured to initiallyengage said first membrane on a surface of said first membrane facingsaid reservoir; wherein, when said pressurizing mechanism is actuated,said piercing member engages and disrupts said first membrane to allowgas to flow through said first membrane and said entrance port and saidreservoir and to carry the medicament through said exit port into saidtube.
 2. The medicament delivery device of claim 1 wherein said deliveryopening of said tube is placed adjacent a facial opening of the user. 3.The medicament delivery device of claim 2 wherein said delivery openingof said tube is placed adjacent a nose of the user.
 4. The medicamentdelivery device of claim 2 wherein said delivery opening of said tube isplaced adjacent a mouth of the user.
 5. The medicament delivery deviceof claim 1 including a medicament disposed in said reservoir.
 6. Themedicament delivery device of claim 10 wherein said medicament is a drypowder.
 7. A medicament delivery device for administering an inhalablemedicament to a user, said device comprising: a medicament reservoir; anentrance port and an exit port each disposed adjacent said reservoir; agas chamber disposed adjacent said entrance port; a pressurizingmechanism defining said gas chamber and operable to pressurize said gaschamber to at least a prescribed pressure; a first frangible membraneextending across said entrance port and separating said reservoir fromsaid gas chamber, said first frangible membrane having a weakeningembossment formed on a surface of said first membrane; a secondfrangible membrane extending across said exit port said second frangiblemembrane having a weakening embossment formed on a surface of saidsecond membrane; a tube disposed adjacent said exit port and defining adelivery opening opposite said exit port; wherein, when saidpressurizing mechanism is actuated, said first membrane is distorted andfirst membrane is disrupted to allow gas to flow through said firstmembrane and said entrance port and said reservoir and to carry themedicament through said exit port.
 8. The medicament delivery device ofclaim 7 including a piercing member configured to initially engage saidfirst membrane on a surface of said first membrane facing saidreservoir.
 9. The medicament delivery device of claim 8 including apiercing member, said piercing member being responsive to saidpressurizing mechanism wherein, when said pressurizing mechanism isactuated, said piercing member engages and disrupts said first membranein said gas chamber to allow gas to flow through said first membrane andsaid entrance port and said reservoir and to carry the medicamentthrough said exit port.
 10. The medicament delivery device of claim 7including a removable end cap configured to rupture said second membraneupon removal of said end cap from said medicament delivery device. 11.The medicament delivery device of claim 7 wherein said delivery openingof said tube is placed adjacent a facial opening of the user.
 12. Themedicament delivery device of claim 11 wherein said delivery opening ofsaid tube is placed adjacent a nose of the user.
 13. The medicamentdelivery device of claim 11 wherein said delivery opening of said tubeis placed adjacent a mouth of the user.
 14. The medicament deliverydevice of claim 7 including a medicament disposed in said reservoir. 15.The medicament delivery device of claim 14 wherein said medicament is adry powder.